Central tube component of filter element and manufacturing method thereof

ABSTRACT

A central tube assembly for a filter cartridge and a manufacturing method for the central tube assembly are provided. The central tube assembly includes a first half-tube defines a first flow passage, and having a first water inlet at an end thereof and a water output hole in a side wall thereof, a filtering membrane bent to form a first membrane layer and a second membrane layer, the first half-tube being disposed between the first membrane layer and the second membrane layer; an input-water filtering net connected to the first half-tube and disposed between the first membrane layer and the second membrane layer, a second half-tube disposed outside of a bending of the filtering membrane, defining a second flow passage, and having a water input hole in a side wall thereof and a first water outlet at an end thereof, and a produced-water filtering net.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present disclosure is a continuation application of U.S. applicationSer. No. 15/749,787, filed on Feb. 2, 2018, which claims the prioritiesof Chinese Applications No. 201520593083.X, 201510481968.5 and201520593260.4 filed in the Chinese Patent Office on Aug. 3, 2015, theentireties of which are herein incorporated by reference.

FIELD

The present disclosure relates to a technical field of waterpurification devices, and more particularly to a central tube assemblyfor a filter cartridge and a manufacturing method thereof.

BACKGROUND

Filtration technologies in the current household water purifier marketgenerally include a microfiltration technology, an ultrafiltrationtechnology, an ion exchange technology, an adsorption technology and areverse osmosis (RO)/nano-filtration (NF) technology. For the RO/NF, thecore component is a RO/NF membrane element. Compared with an industrialmembrane element, the membrane in a household water purifier has a shortflow passage. A water feeding manner for a traditional membrane elementis that raw water is introduced in and concentrated water is dischargedout in a direction parallel to a purified-water collection tube (acentral tube). Since the flow passage is relatively short, the flowingspeed in the membrane is poor in the case of equal water inlet flow,such that the membrane surface tends to produce a strong concentrationpolarization, and hence to be polluted, thus resulting in a low wateruse efficiency of the existing household water purifier.

SUMMARY

Embodiments of the present disclosure seek to solve at least one of theproblems existing in the related art to at least some extent.

For that reason, the present disclosure provides a central tube assemblyfor a filter cartridge. The central tube assembly is simple instructure, convenient for moldmaking, suitable for mass production, highin water flowing speed, and not easy to be polluted.

The present disclosure also provides a manufacturing method for acentral tube assembly for a filter cartridge.

The central tube assembly for the filter cartridge according toembodiments of a first aspect of the present disclosure includes a firsthalf-tube, the first half-tube having a first flow passage extending inan axial direction of the first half-tube, an end of the first half-tubehaving a first water inlet communicated with the first flow passage, aside wall of the first half-tube having a water output hole communicatedwith the first flow passage; a filtering membrane, the filteringmembrane having a side formed as a raw-water side and another sideformed as a produced-water side, the filtering membrane being benttowards the raw-water side to form a first membrane layer and a secondmembrane layer, the first half-tube being disposed between the firstmembrane layer and the second membrane layer and adjacent to a bendingposition; an input-water filtering net, the input-water filtering netbeing connected with the first half-tube, the input-water filtering netbeing disposed between the first membrane layer and the second membranelayer, so as to define a waste water passage between the first membranelayer and the second membrane layer; a second half-tube, the secondhalf-tube being disposed outside of a bending of the filtering membraneand adjacent to the first half-tube, the second half-tube having asecond flow passage extending in an axial direction of the secondhalf-tube, a side wall of the second half-tube having a water input holecommunicated with the second flow passage, an end of the secondhalf-tube having a first water outlet communicated with the second flowpassage; a produced-water filtering net, the produced-water filteringnet being connected with the second half-tube, the produced-waterfiltering net, the first membrane layer and the second membrane layerbeing coiled on the first half-tube and the second half-tube in a samedirection, so as to fix the first half-tube with the second half-tube,the produced-water filtering net being disposed between the firstmembrane layer and the second half-tube, so as to define a purifiedwater passage between the first membrane layer and the second half-tube,in which the purified water passage is communicated with the water inputhole.

In the central tube assembly for the filter cartridge according toembodiments of the present disclosure, the central tube is constitutedby two pipe bodies, i.e. the first half-tube and the second half-tube.After the raw water enters the central tube, during operations of themembrane elements, the flowing direction of water is all alongperpendicular to the direction of the central tube, such that negativeeffects caused by changes of a direction of a flowing speed in themembrane can be avoided while ensuring the flowing speed in themembrane, and a pollution-resistance property of the membrane isimproved under the premise of mass production.

In addition, the central tube assembly for the filter cartridgeaccording to embodiments of the present disclosure also includesfollowing additional technical features.

According to an embodiment of the present disclosure, the central tubeassembly for the filter cartridge further includes: an upper-end cover,the upper-end cover having a second water inlet communicated with thefirst water inlet and a second water outlet communicated with the firstwater outlet, the upper-end cover being fitted over upper ends of thefirst half-tube and the second half-tube, the upper-end cover tightlypressing an upper end of the filtering membrane, so as to seal an upperend of the central tube assembly; and a lower-end cover, the lower-endcover being fitted over lower ends of the first half-tube and the secondhalf-tube, the lower-end cover tightly pressing a lower end of thefiltering membrane, so as to seal a lower end of the central tubeassembly.

According to an embodiment of the present disclosure, a section of thefirst half-tube and a section of the second half-tube each have asemicircle shape, the water output hole is provided in an arc surface ofthe first half-tube, the water input hole is provided in an arc surfaceof the second half-tube, and a flat surface of the first half-tube isarranged opposite to a flat surface of the second half-tube.

According to an embodiment of the present disclosure, a surface of thefirst half-tube, which is arranged opposite to the second half-tube, isslotted and provided with the first flow passage, and a surface of thesecond half-tube, which is arranged opposite to the first half-tube, isslotted and provided with the second flow passage.

According to an embodiment of the present disclosure, at least one of asurface of the first half-tube and a surface of the second half-tube isprovided with a reinforcing rib, in which the surface of the firsthalf-tube is arranged opposite to the surface of the second half-tube,and the reinforcing rib abuts against the filtering membrane.

According to an embodiment of the present disclosure, two ends of thefirst half-tube each are provided with a first pre-mounting portionbeyond the filtering membrane, two ends of the second half-tube each areprovided with a second pre-mounting portion beyond the filteringmembrane, and the first pre-mounting portion is connected to the secondpre-mounting portion before the filtering membrane is coiled.

According to an embodiment of the present disclosure, the firstpre-mounting portion includes a first upper fitting part provided at anupper end of the first half-tube and a first lower fitting part providedat a lower end of the first half-tube, the second pre-mounting portionincludes a second upper fitting part provided at an upper end of thesecond half-tube and a second lower fitting part provided at a lower endof the second half-tube, the first upper fitting part and the secondupper fitting part are corresponding in structure and connected to forma cylindrical structure, and the first lower fitting part and the secondlower fitting part are corresponding in structure and connected to forma cylindrical structure.

According to an embodiment of the present disclosure, the firstpre-mounting portion further includes a first upper bonding partprovided at the upper end of the first half-tube and a first lowerbonding part provided at the lower end of the first half-tube, the firstupper bonding part is located below the first upper fitting part, andthe first lower bonding part is located above the first lower fittingpart; the second pre-mounting portion further includes a second upperbonding part provided at the upper end of the second half-tube and asecond lower bonding part provided at the lower end of the secondhalf-tube, the second upper bonding part is located below the secondupper fitting part, and the second lower bonding part is located abovethe second lower fitting part.

According to an embodiment of the present disclosure, the first upperbonding part and the second upper bonding part each are provided with asealing glue layer, and the first lower bonding part and the secondlower bonding part each are provided with a sealing glue layer.

According to an embodiment of the present disclosure, the firstpre-mounting portion is integrally formed with the first half-tube, andthe second pre-mounting portion is integrally formed with the secondhalf-tube.

According to an embodiment of the present disclosure, a distance betweenthe second water inlet of the upper-end cover and the second wateroutlet of the upper-end cover is 20-50 mm.

According to an embodiment of the present disclosure, a lower surface ofthe upper-end cover and an upper surface of the lower-end cover each areprovided with a sealing glue layer.

The manufacturing method for the central tube assembly for the filtercartridge according to embodiments of a second aspect of the presentdisclosure includes following steps: S1, bending a filtering membranetowards a raw-water side, so as to form a first membrane layer and asecond membrane layer, connecting an input-water filtering net with afirst half-tube and arranging the input-water filtering net connectedwith the first half-tube between the first membrane layer and the secondmembrane layer and adjacent to a bending position of the filteringmembrane; S2, connecting a produced-water filtering net with a secondhalf-tube, arranging the second half-tube adjacent to the firsthalf-tube and outside of a bending of the filtering membrane, connectingan upper end of the first half-tube with an upper end of the secondhalf-tube, and connecting a lower end of the first half-tube with alower end of the second half-tube; S3, coiling the produced-waterfiltering net, the first membrane layer and the second membrane layer onthe first half-tube and the second half-tube in a same direction, so asto fix the first half-tube with the second half-tube; S4, fitting anupper-end cover over upper ends of the first half-tube and the secondhalf-tube, tightly pressing the upper end of the filtering membrane,fitting a lower-end cover over lower ends of the first half-tube and thesecond half-tube, tightly pressing a lower end of the filteringmembrane, thereby obtaining the central tube assembly.

According to an embodiment of the present disclosure, the two ends ofthe first half-tube each are provided with a first pre-mounting portionbeyond the filtering membrane, the two ends of the second half-tube eachare provided with a second pre-mounting portion beyond the filteringmembrane, the first pre-mounting portion and the second pre-mountingportion are connected before the filtering membrane is coiled, and thefirst pre-mounting portion and the second pre-mounting portion are cutoff after the filtering membrane completes coiling.

According to an embodiment of the present disclosure, step S4 furtherincludes following steps: S41, coating glue on a lower surface of theupper-end cover and on an upper surface of the lower-end cover; S42,fitting the upper-end cover over the upper ends of the first half-tubeand the second half-tube, tightly pressing the upper end of thefiltering membrane by the upper-end cover to form a sealing glue layer,fitting the lower-end cover over the lower ends of the first half-tubeand the second half-tube, tightly pressing the lower end of thefiltering membrane by the lower-end cover to form a sealing glue layer,thereby obtaining the central tube assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will become apparent and morereadily appreciated from the following descriptions made with referenceto the drawings, in which:

FIG. 1 is a schematic view of a first half-tube of a central tubeassembly according to embodiments of the present disclosure;

FIG. 2 is a side view of a first half-tube of a central tube assemblyaccording to embodiments of the present disclosure;

FIG. 3 is a schematic view of a second half-tube of a central tubeassembly according to embodiments of the present disclosure;

FIG. 4 is a side view of a second half-tube of a central tube assemblyaccording to embodiments of the present disclosure;

FIG. 5 is a schematic view of an upper-end cover and a lower-end coverof a central tube assembly according to embodiments of the presentdisclosure;

FIG. 6 is an assembling view of a central tube assembly according toembodiments of the present disclosure;

FIG. 7 is a flow chart of a manufacturing method for a central tubeassembly according to embodiments of the present disclosure.

REFERENCE NUMERALS

-   -   Central tube assembly 100;    -   First half-tube 10; first flow passage 11; first water inlet 12;        water output hole 13; reinforcing rib 14; first upper fitting        part 15; first lower fitting part 16; first upper bonding part        17; first lower bonding part 18; tooling bayonet 19;    -   Second half-tube 20; second flow passage 21; water input hole        22; first water outlet 23; second upper fitting part 25; second        lower fitting part 26; second upper bonding part 27; second        lower bonding part 28;    -   Filtering membrane 30; input-water filtering net 40;        produced-water filtering net 50;    -   Upper-end cover 60; second water inlet 61; second water outlet        62;    -   Lower-end cover 70.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail in thefollowing. Examples of the embodiments are illustrated in theaccompanying drawings. The same or similar elements and the elementshaving same or similar functions are denoted by like reference numeralsthroughout the descriptions. The embodiments described herein withreference to drawings are explanatory and used to generally understandthe present disclosure. The embodiments shall not be construed to limitthe present disclosure.

A central tube assembly 100 for a filter cartridge according toembodiments of the present disclosure will be described in detail withreference to the drawings in the following.

As shown in FIGS. 1-6, the central tube assembly 100 for the filtercartridge according to embodiments of the present disclosure includes afirst half-tube 10, a second half-tube 20, a filtering membrane 30, aninput-water filtering net 40, a produced-water filtering net 50, anupper-end cover 60, and a lower-end cover 70.

In one embodiment, the first half-tube 10 has a first flow passage 11extending in an axial direction of the first half-tube 10. An end of thefirst half-tube 10 has a first water inlet 12 communicated with thefirst flow passage 11. A side wall of the first half-tube 10 has a wateroutput hole 13 communicated with the first flow passage 11. Thefiltering membrane 30 has a side configured as a raw-water side andanother side configured as a produced-water side. The filtering membrane30 is bent towards the raw-water side to form a first membrane layer anda second membrane layer. The first half-tube 10 is disposed between thefirst membrane layer and the second membrane layer and adjacent to abending position. The input-water filtering net 40 is connected with thefirst half-tube 10. The input-water filtering net 40 is disposed betweenthe first membrane layer and the second membrane layer, so as to definea waste water passage between the first membrane layer and the secondmembrane layer.

The second half-tube 20 is disposed outside of a bending of thefiltering membrane 30 and adjacent to the first half-tube 10. The secondhalf-tube 20 has a second flow passage 21 extending in an axialdirection of the second half-tube 20. A side wall of the secondhalf-tube 20 has a water input hole 22 communicated with the second flowpassage 21. An end of the second half-tube 20 has a first water outlet23 communicated with the second flow passage 21. The produced-waterfiltering net 50 is connected with the second half-tube 20. Theproduced-water filtering net 50, the first membrane layer and the secondmembrane layer are wound on the first half-tube 10 and the secondhalf-tube 20 in a same direction, so as to fix the first half-tube 10and the second half-tube 20. The produced-water filtering net 50 isdisposed between the first membrane layer and the second half-tube 20,so as to define a purified water passage between the first membranelayer and the second half-tube 20, in which the purified water passageis communicated with the water input hole 22.

The upper-end cover 60 has a second water inlet 61 communicated with thefirst water inlet 12 and a second water outlet 62 communicated with thefirst water outlet 23. The upper-end cover 60 is fitted over upper endsof the first half-tube 10 and the second half-tube 20. The upper-endcover 60 tightly presses an upper end of the filtering membrane 30, soas to seal an upper end of the central tube assembly. The lower-endcover 70 is fitted over lower ends of the first half-tube 10 and thesecond half-tube 20. The lower-end cover 70 tightly presses a lower endof the filtering membrane 30, so as to seal a lower end of the centraltube assembly.

In other words, the central tube assembly 100 according to embodimentsof the present disclosure mainly includes the first half-tube 10, thesecond half-tube 20, the filtering membrane 30, the input-waterfiltering net 40, the produced-water filtering net 50, the upper-endcover 60 and the lower-end cover 70. That is, the central tub is acylindrical tube body constituted by the first half-tube 10 and thesecond half-tube 20 together.

The first half-tube 10 has the first flow passage 11 extending in theaxial direction of the first half-tube 10. The end of the firsthalf-tube 10 has the first water inlet 12 communicated with the firstflow passage 11. The side wall of the first half-tube 10 has the wateroutput hole 13 communicated with the first flow passage 11. The secondhalf-tube 20 has the second flow passage 21 extending in the axialdirection of the second half-tube 20. The end of the second half-tube 20has the first water outlet 23 communicated with the second flow passage21. The side wall of the second half-tube 20 has the water input hole 22communicated with the second flow passage 21.

The filtering membrane 30 has two sides, one of the two sides is formedas the raw-water side, and the other one of the two sides is formed asthe produced-water side. The filtering membrane 30 is folded towards theraw-water side to form the first membrane layer and the second membranelayer. The bending is formed in a position where the filtering membrane30 is folded. The first half-tube 10 is disposed between the firstmembrane layer and the second membrane layer and adjacent to the bendingposition.

The input-water filtering net 40 is disposed between the first membranelayer and the second membrane layer and is connected with the firsthalf-tube 10. After the input-water filtering net 40 and the filteringmembrane 30 are coiled together, the waste water passage is definedbetween the first membrane layer and the second membrane layer. A rawwater flowing out of the water output hole 13 of the first half-tube 10flows to the waste water passage between the first membrane layer andthe second membrane layer in a direction perpendicular to the firsthalf-tube 10. After the raw water is filtered by the filtering membrane30, the remaining waste water continues flowing outwards along the wastewater passage, until it flows out of the central tube assembly 100.

The second half-tube 20 is adjacent to the first half-tube 10 and islocated outside of the bending of the first membrane layer and thesecond membrane layer. The second half-tube 20 is connected with theproduced-water filtering net 50. The produced-water filtering net 50 iscoiled with the input-water filtering net 40 and the filtering membrane30. The produced-water filtering net 50 is coiled between the filteringmembrane 30 and the second half-tube 20, and the purified water passageis defined between the filtering membrane 30 and the second half-tube20. The purified water passage is communicated with the water input hole22 of the second half-tube 20.

After the raw water is filtered by the filtering membrane 30, thepurified water obtained by filtration flows to the purified waterpassage in a direction perpendicular to the second half-tube 20, entersthe second flow passage 21 through the water input hole 22, and flowsout of the first water outlet 23, such that circulation directions ofthe raw water and the purified water in the membrane elements of theoverall central tube assembly 100 both are perpendicular to the firsthalf-tube 10 and the second half-tube 20, thus avoiding negative effectscaused by changes of water flowing directions.

The upper-end cover 60 is fitted over the upper ends of the firsthalf-tube 10 and the second half-tube 20. The second water inlet 61 ofthe upper-end cover 60 is fitted and communicated with the first waterinlet 12. The second water outlet 62 of the upper-end cover 60 is fittedand communicated with the first water outlet 23. The upper-end cover 60tightly presses the upper end of the filtering membrane 30 to form aclosed structure, so as to seal the upper end of the central tubeassembly. The lower-end cover 70 tightly presses the lower end of thefiltering membrane 30 to form a closed structure, so as to seal thelower end of the central tube assembly. The central tube assembly 100 isfixed by the upper-end cover 60 and the lower-end cover 70 to form astructure which is sealed at top and bottom, thereby greatly improvingthe working efficiency and feasibility of assembling.

Thus, in the central tube assembly 100 for the filter cartridgeaccording to embodiments of the present disclosure, the central tube isconstituted by the first half-tube 10 and the second half-tube 20. Afterthe raw water enters the central tube, during operations of the membraneelements, the flowing direction of water is all along perpendicular tothe central tube, such that negative effects caused by changes of adirection of a flowing speed in the membrane can be avoided whileensuring the flowing speed in the membrane, a pollution-resistanceproperty of the membrane is improved under the premise of massproduction, and the assembling of the central tube assembly is achievedby the upper-end cover 60 and the lower-end cover 70, thus providinghigh assembling efficiency and facilitating mass production.

According to an embodiment of the present disclosure, a section of thefirst half-tube 10 and a section of the second half-tube 20 each have asemicircle shape. The water output hole 13 is provided to an arc surfaceof the first half-tube 10, the water input hole 22 is provided to an arcsurface of the second half-tube 20, and a flat surface of the firsthalf-tube 10 is arranged opposite to a flat surface of the secondhalf-tube 20.

Thus, the first half-tube 10 having the semicircle section and thesecond half-tube 20 having the semicircle section can form a circularstructure after being fitted with each other. The circular structure issimilar to a cylindrical central tube structure of a traditionalconstruction, is convenient to mount and can also be greatly fitted withdevices of other traditional structures.

In one embodiment, the surface of the first half-tube 10, which isopposite to the second half-tube 20, is slotted and provided with thefirst flow passage 11, and the surface of the second half-tube 20, whichis opposite to the first half-tube 10, is slotted and provided with thesecond flow passage 21.

In one embodiment, as shown in FIGS. 1 and 3, in the presentapplication, the first flow passage 11 in the first half-tube 10 and thesecond flow passage 21 in the second half-tube 20 can be formed byslotting respectively, thereby achieving the moldmaking production.Since the filtering membrane 30 is wrapped outside the first half-tube10, even though the raw water entering the first flow passage 11 throughthe first water inlet 12 penetrates the filtering membrane 30 and flowsinto the second flow passage 21 of the second half-tube 20, the waterflowing into the second flow passage 21 is the purified water and willnot influence a normal use of the central tube assembly 100.

According to an embodiment of the present disclosure, at least one ofthe surface of the first half-tube 10 and the surface of the secondhalf-tube 20 arranged opposite to the surface of the first half-tube 10is provided with a reinforcing rib 14, and the reinforcing rib 14 abutsagainst the filtering membrane 30. In one embodiment, the surface of thefirst half-tube 10 and the surface of the second half-tube 20 arrangedopposite to the surface of the first half-tube 10 each are provided withthe reinforcing rib 14.

Thus, by providing the reinforcing rib 14 on half-open surfacestructures of the first half-tube 10 and the second half-tube 20respectively, it is possible to ensure a supporting force for thefiltering membrane 30, thereby serving to reinforce a strength of thecentral tube.

In some embodiments, two ends of the first half-tube 10 each areprovided with a first pre-mounting portion beyond the filtering membrane30, two ends of the second half-tube 20 each are provided with a secondpre-mounting portion beyond the filtering membrane 30, and the firstpre-mounting portion is connected with the second pre-mounting portionbefore the filtering membrane 30 is coiled.

That is, in the present application, the two ends of the first half-tube10 and the two ends of the second half-tube 20 each have a portion wherethe filtering membrane 30 is not necessary to be coiled, i.e., the firstpre-mounting portion and the second pre-mounting portion. When the firsthalf-tube 10, the second half-tube 20, the filtering membrane 30, theinput-water filtering net 40 and the produced-water filtering net 50 arearranged in position, the first half-tube 10 and the second half-tube 20can be first connected through the first pre-mounting portion and thesecond pre-mounting portion, such that the central tube can be steadilymounted in a coiling machine during a coiling process, thus achieving amechanized production. When the coiling is completed, the firstpre-mounting portion and the second pre-mounting portion can be cut offrespectively, and then the upper-end cover 60 and the lower-end cover 70can be mounted, thereby greatly improving the assembling efficiency.

As shown in FIG. 6, in FIG. 6, the first pre-mounting portion at theupper end of the first half-tube 10 and the second pre-mounting portionat the upper end of the second half-tube 20 are in a non-cut-off state,while the first pre-mounting portion at the lower end of the firsthalf-tube 10 and the second pre-mounting portion at the lower end of thesecond half-tube 20 have been cut off.

In one embodiment, the first pre-mounting portion includes a first upperfitting part 15 provided at the upper end of the first half-tube 10 anda first lower fitting part 16 provided at the lower end of the firsthalf-tube 10. The second pre-mounting portion includes a second upperfitting part 25 provided at the upper end of the second half-tube 20 anda second lower fitting part 26 provided at the lower end of the secondhalf-tube 20. The first upper fitting part 15 and the second upperfitting part 25 are corresponding in structure and connected to form acylindrical structure, and the first lower fitting part 16 and thesecond lower fitting part 26 are corresponding in structure andconnected to form a cylindrical structure.

In one embodiment, the first pre-mounting portion also includes a firstupper bonding part 17 provided at the upper end of the first half-tube10 and a first lower bonding part 18 provided at the lower end of thefirst half-tube 10. The first upper bonding part 17 is located below thefirst upper fitting part 15, and the first lower bonding part 18 islocated above the first lower fitting part 16. The second pre-mountingportion also includes a second upper bonding part 27 provided at theupper end of the second half-tube 20 and a second lower bonding part 28provided at the lower end of the second half-tube 20, the second upperbonding part 27 is located below the second upper fitting part 25, andthe second lower bonding part 28 is located above the second lowerfitting part 26.

As shown in FIGS. 1 and 3, in the present application, the upper andlower ends of the first half-tube 10 are respectively provided with thefirst pre-mounting portion, the upper and lower ends of the secondhalf-tube 20 are respectively provided with the second pre-mountingportion, and the first pre-mounting portion can be fitted with thesecond pre-mounting portion. The first pre-mounting portion includes thefirst upper fitting part 15 located at the upper end of the firsthalf-tube 10 and the first lower fitting part 16 located at the lowerend of the first half-tube 10. The second pre-mounting portion includesthe second upper fitting part 25 located at the upper end of the secondhalf-tube 20 and the second lower fitting part 26 located at the lowerend of the second half-tube 20.

The first upper fitting part 15 and the second upper fitting part 25 arecorresponding in structure and form a cylindrical structure after thefirst half-tube 10 and the second half-tube 20 are connected.Correspondingly, the first lower fitting part 16 and the second lowerfitting part 26 are corresponding in structure and form a cylindricalstructure after the first half-tube 10 and the second half-tube 20 areconnected. In one embodiment, for example, when the first upper fittingpart 15 is configured as a recessed structure, the second upper fittingpart 25 is configured as a protrusion structure corresponding to therecessed structure, such that the two structures can substantially forma cylindrical structure after being fitted to each other.

The fitting structure of the first upper fitting part 15 and the secondupper fitting part 25 as well as the fitting structure of the firstlower fitting part 16 and the second lower fitting part 26, canfacilitate the positioning and assembling of the first half-tube 10 andthe second half-tube 20, and can also be conveniently cut off after thefirst half-tube 10 and the second half-tube 20 are wound by thefiltering membrane 30, thereby achieving the mechanized production.

The first pre-mounting portion also includes the first upper bondingpart 17 and the first lower bonding part 18, and the second pre-mountingportion also includes the second upper bonding part 27 and the secondlower bonding part 28. The first upper bonding part 17 and the firstlower bonding part 18 are disposed at two ends of the first half-tube 10respectively and located between the first upper fitting part 15 and thefirst lower fitting part 16. The second upper bonding part 27 and thesecond lower bonding part 28 are disposed at two ends of the secondhalf-tube 20 respectively and located between the second upper fittingpart 25 and the second lower fitting part 26.

In one embodiment, the lower end of the first half-tube 10 can also beprovided with a tooling bayonet 19. The structure of the tooling bayonet19 facilitates the mounting of a tooling fixture, such that it is moreconvenient for the assembling of the first half-tube 10 and the secondhalf-tube 20.

According to an embodiment of the present disclosure, the first upperbonding part 17 and the second upper bonding part 27 each are providedwith a sealing glue layer, and the first lower bonding part 18 and thesecond lower bonding part 28 each are also provided with a sealing gluelayer.

That is, during the assembling, the first upper bonding part 17 and thefirst lower bonding part 18, as well as the second upper bonding part 27and the second lower bonding part 28 can be provided with a smallquantity of bonding-surface sealing glue, thereby facilitating theconnection between the first upper bonding part 17 and the second upperbonding part 27 as well as the connection between the first lowerbonding part 18 and second lower bonding part 28.

In some embodiments, the first pre-mounting portion is integrally formedwith the first half-tube 10, and the second pre-mounting portion isintegrally formed with the second half-tube 20.

Thus, the structures of the integrally formed first half-tube 10 and theintegrally formed second half-tube 20 ensure the overall structuralstability and are convenient to be molded, such that the productionefficiency is improved and the cost is low.

According to an embodiment of the present disclosure, a distance betweenthe second water inlet 61 and the second water outlet 62 of theupper-end cover 60 is 20-50 mm. Thus, the upper-end cover 60 of thisstructure facilitates the moldmaking production. In addition, during themoldmaking production, a core pulling may be performed in respect of thefirst water inlet 12 of the first half-tube 10 and the first wateroutlet 23 of the second half-tube 20, and can also be performed inrespect of the tooling bayonet 19. A core pilling distance is 20-50 mm.

Furthermore, a lower surface of the upper-end cover 60 and an uppersurface of the lower-end cover 70 each are provided with a sealing gluelayer.

In one embodiment, after the central tube assembly 100 completes thecoiling and the first pre-mounting portion and the second pre-mountingportion are cut off, the glue is coated in the upper-end cover 60, thesecond water inlet 61 of the upper-end cover 60 is fitted andcommunicated with the first water inlet 12, the second water outlet 62of the upper-end cover 60 is fitted and communicated with the firstwater outlet 23, and the upper-end cover 60 tightly presses the upperend of the filtering membrane 30 to form the closed structure, therebysealing the upper end of the central tube assembly 100.

Then, the glue is coated in the lower-end cover 70, the lower-end cover70 tightly presses the lower end of the filtering membrane 30 to formthe closed structure, so as to seal the lower end of the central tubeassembly, such that upper edges of the input-water filtering net 40 andthe produced-water filtering net 50 are bonded with the upper end of thefiltering membrane 30, and lower edges of the input-water filtering net40 and the produced-water filtering net 50 are bonded with the lower endof the filtering membrane 30, thereby providing the sealing effects. Thecentral tube assembly 100 is fixed by the upper-end cover 60 and thelower-end cover 70 to form a structure which is sealed at top andbottom, thereby greatly improving the working efficiency and feasibilityof assembling.

During the filtration of the central tube assembly 100 according toembodiments of the present disclosure, the raw water enters through thefirst water inlet 12, flows through the first flow passage 11, entersthe filtering membrane 30 through the water output hole 13, and flowsalong the input-water filtering net 40. Finally, the concentrated waterflows out of an outlet of the waste water passage. The produced waterpenetrates the filtering membrane 30, then flows to the second half-tube20 along the produced-water filtering net 50, flows through the waterinput hole 22, further flows through the second flow passage 21, andflows out of the first water outlet 23.

When the central tube assembly 100 according to embodiments of thepresent disclosure is filtering, during the operations of the membraneelements, the flowing direction of the raw water is all alongperpendicular to the direction of the central tube, such that thenegative effects caused by changes of the direction of the flowing speedin the membrane can be avoided while ensuring the flowing speed in themembrane, and the pollution-resistance property of the membrane elementis improved under the premise of mass production.

A manufacturing method for the central tube assembly 100 for the filtercartridge according to above embodiments of the present disclosure willbe described in detail with reference to FIG. 7.

In one embodiment, as shown in FIG. 7, the manufacturing method for thecentral tube assembly 100 for the filter cartridge according toembodiments of the present disclosure includes following method.

At S1, the filtering membrane 30 is bent towards the raw-water side soas to form the first membrane layer and the second membrane layer, theinput-water filtering net 40 is connected with the first half-tube 10,and then arranged between the first membrane layer and the secondmembrane layer and adjacent to the bending position of the filteringmembrane 30.

At S2, the produced-water filtering net 50 is connected with the secondhalf-tube 20, the second half-tube 20 is arranged adjacent to the firsthalf-tube 10 and outside of the bending of the filtering membrane 30,upper ends of the first half-tube 10 and the second half-tube 20 areconnected, and lower ends of the first half-tube 10 and the secondhalf-tube 20 are connected.

At S3, the produced-water filtering net 50, the first membrane layer andthe second membrane layer are coiled on the first half-tube 10 and thesecond half-tube 20 in a same direction, so as to fix the firsthalf-tube 10 with the second half-tube 20.

At S4, the upper-end cover 60 is fitted over the upper ends of the firsthalf-tube 10 and the second half-tube 20, and tightly presses the upperend of the filtering membrane 30, the lower-end cover 70 is fitted overthe lower ends of the first half-tube 10 and the second half-tube 20,and tightly presses the lower end of the filtering membrane 30, therebyobtaining the central tube assembly.

Thus, for the manufacturing method of the central tube assembly 100according to embodiments of the present disclosure, operability isstrong, feasibility is high, the moldmaking production and themechanized production are easy, and the production cost is reduced.

In one embodiment, two ends of the first half-tube 10 each are providedwith the first pre-mounting portion beyond the filtering membrane 30,and two ends of the second half-tube 20 each are provided with thesecond pre-mounting portion beyond the filtering membrane 30. The firstpre-mounting portion and the second pre-mounting portion are connectedbefore the filtering membrane 30 is coiled. The first pre-mountingportion and the second pre-mounting portion are cut off after thefiltering membrane 30 completes coiling.

Furthermore, S4 also includes following.

At S41, glue is coated on a lower surface of the upper-end cover 60 andalso coated on an upper surface of the lower-end cover 70.

At S42, the upper-end cover 60 is fitted over the upper ends of thefirst half-tube 10 and the second half-tube 20, the upper-end cover 60tightly presses the upper end of the filtering membrane 30 to form thesealing glue layer, the lower-end cover 70 is fitted over the lower endsof the first half-tube 10 and the second half-tube 20, the lower-endcover 70 tightly presses the lower end of the filtering membrane 30 toform the sealing glue layer, thereby obtaining the central tubeassembly.

In one embodiment, the manufacturing method for the central tubeassembly 100 for the filter cartridge according to embodiments of thepresent disclosure may include the following.

First, the filtering membrane 30 is folded towards the raw-water side,and the raw-water side faces inwards. The first half-tube 10 and theinput-water filtering net 40 connected thereto are put in the foldedmembrane. The first upper fitting part 15 is fitted with the secondupper fitting part 25, and the first lower fitting part 16 is fittedwith the second lower fitting part 26. The produced-water filtering net50 is arranged at the produced-water side of the filtering membrane 30.A small amount of upper bonding-surface sealing glue is spread in abonding position of the first upper bonding part 17 and the second upperbonding part 27, and a small amount of lower bonding-surface sealingglue is spread in a bonding position of the first lower bonding part 18and the second lower bonding part 28.

Then, the filtering membrane 30, the input-water filtering net 40, theproduced-water filtering net 50 are coiled around the central tubeconstituted by the first half-tube 10 and the second half-tube 20. Thesealing glue is spread at ends of two produced-water sides of thefiltering membrane 30 away from the central tube, i.e., theproduced-water sides of the first membrane and the second membrane.Portions above the first upper bonding part 17 and the second upperbonding part 27 as well as portions below the first lower bonding part18 and the second lower bonding part 28 are cut off, that is, the firstpre-mounting portion and the second pre-mounting portion are cut off.

Then, the glue is coated in the upper-end cover 60, the second waterinlet 61 of the upper-end cover 60 is fitted and communicated with thefirst water inlet 12, and the second water outlet 62 of the upper-endcover 60 is fitted and communicated with the first water outlet 23. Theupper-end cover 60 tightly presses the upper end of the filteringmembrane 30 to form the closed structure, thereby sealing the upper endof the central tube assembly 100.

Finally, the glue is coated in the lower-end cover 70, and the lower-endcover 70 tightly presses the lower end of the filtering membrane 30 toform the closed structure, so as to seal the lower end of the centraltube assembly, such that the upper edges of the input-water filteringnet 40 and the produced-water filtering net 50 are bonded with the upperend of the filtering membrane 30, and the lower edges of the input-waterfiltering net 40 and the produced-water filtering net 50 are bonded withthe lower end of the filtering membrane 30, thereby providing thesealing effects. The central tube assembly 100 is fixed by the upper-endcover 60 and the lower-end cover 70 to form a structure which is sealedat top and bottom, thereby greatly improving the working efficiency andfeasibility of assembling.

Other components and operations of the central tube assembly 100 for thefilter cartridge according to embodiments of the present disclosure.

In the specification, it is to be understood that terms such as“central,” “longitudinal,” “lateral,” “length,” “width,” “thickness,”“upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,”“horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and“counterclockwise” should be construed to refer to the orientation asthen described or as shown in the drawings under discussion. Theserelative terms are for convenience of description and do not requirethat the present disclosure be constructed or operated in a particularorientation.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance or to imply the number of indicatedtechnical features. Thus, the feature defined with “first” and “second”may comprise one or more of this feature. In the description of thepresent disclosure, “a plurality of” means two or more than two, unlessspecified otherwise.

In the present disclosure, unless specified or limited otherwise, theterms “mounted,” “connected,” “coupled,” “fixed” and the like are usedbroadly, and may be, for example, fixed connections, detachableconnections, or integral connections; may also be mechanical orelectrical connections; may also be direct connections or indirectconnections via intervening structures; may also be inner communicationsof two elements.

In the present disclosure, unless specified or limited otherwise, astructure in which a first feature is “on” or “below” a second featuremay include an embodiment in which the first feature is in directcontact with the second feature, and may also include an embodiment inwhich the first feature and the second feature are not in direct contactwith each other, but are contacted via an additional feature formedtherebetween. Furthermore, a first feature “on,” “above,” or “on top of”a second feature may include an embodiment in which the first feature isright or obliquely “on,” “above,” or “on top of” the second feature, orjust means that the first feature is at a height higher than that of thesecond feature; while a first feature “below,” “under,” or “on bottomof” a second feature may include an embodiment in which the firstfeature is right or obliquely “below,” “under,” or “on bottom of” thesecond feature, or just means that the first feature is at a heightlower than that of the second feature.

Reference throughout this specification to “an embodiment,” “someembodiments,” “one embodiment”, “another example,” “an example,” “aspecific example,” or “some examples,” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, the appearances of the phrases such as“in some embodiments,” “in one embodiment”, “in an embodiment”, “inanother example,” “in an example,” “in a specific example,” or “in someexamples,” in various places throughout this specification are notnecessarily referring to the same embodiment or example of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments or examples.

What is claimed is:
 1. A manufacturing method for a central tubeassembly for a filter cartridge, comprising: bending a filteringmembrane towards a raw-water side to form a first membrane layer and asecond membrane layer, connecting an input-water filtering net with afirst half-tube, then arranging the input-water filtering net connectedwith the first half-tube between the first membrane layer and the secondmembrane layer and adjacent to a bending position of the filteringmembrane; connecting a produced-water filtering net with a secondhalf-tube, arranging the second half-tube adjacent to the firsthalf-tube and outside of a bending of the filtering membrane, connectingan upper end of the first half-tube with an upper end of the secondhalf-tube, and connecting a lower end of the first half-tube with alower end of the second half-tube; coiling the produced-water filteringnet, the first membrane layer and the second membrane layer on the firsthalf-tube and the second half-tube in a same direction to fix the firsthalf-tube with the second half-tube; fitting an upper-end cover overupper ends of the first half-tube and the second half-tube, tightlypressing an upper end of the filtering membrane, fitting a lower-endcover over lower ends of the first half-tube and the second half-tube,tightly pressing a lower end of the filtering membrane, therebyobtaining the central tube assembly.
 2. The manufacturing methodaccording to claim 1, wherein the two ends of the first half-tube eachare provided with a first pre-mounting portion beyond the filteringmembrane, the two ends of the second half-tube each are provided with asecond pre-mounting portion beyond the filtering membrane, the firstpre-mounting portion and the second pre-mounting portion are connectedbefore the filtering membrane is coiled, and the first pre-mountingportion and the second pre-mounting portion are cut off after thefiltering membrane completes coiling.
 3. The manufacturing methodaccording to claim 1, wherein the fitting of the upper-end cover furthercomprises: coating glue on a lower surface of the upper-end cover and onan upper surface of the lower-end cover; and fitting the upper-end coverover the upper ends of the first half-tube and the second half-tube,tightly pressing the upper end of the filtering membrane by theupper-end cover to form a sealing glue layer, fitting the lower-endcover over the lower ends of the first half-tube and the secondhalf-tube, tightly pressing the lower end of the filtering membrane bythe lower-end cover to form a sealing glue layer, thereby obtaining thecentral tube assembly.